Fig. 9.
Expression of programmed cell death phenotype in wounded and senescing cells in lettuce fresh-cuts, stored at 4 °C a Dead epidermal cells (with accumulated H2O2) at the cut surface, DAB staining; note the brown coloured protoplasts. b Dead epidermal cells in senescing fresh-cut, Evans Blue staining. c Dead mesophyll cells in senescing fresh-cut (epidermis removed), Evans Blue staining. d PI stained condensed nuclei (bright red fluorescence) in dead cells in senescing sites. a–c Note the shrunken protoplast retracted from the cell wall and b, d Condensed nuclei. a–c Some of the cells appear empty, DAB and Evans Blue negative. Samples were taken on day 4 of storage. cw Cell wall, dc Death cell, ec Empty cell, lc Living cell, n Nucleus, p Protoplast, t Trichome. Scale bars = 100 μm